<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <link rel="shortcut icon" href="#" type="image/x-icon">
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
    <div id="app">{{message}}</div>
    <script>
        new Vue({
            el:"#app",  //是"el"，不是"e1"
            data:{
                message:'Hello Vue!'
            }
        });
    </script>
</body>
</html>